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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- c -*- --------------------------------------------------------------- *
2 *
3 * linux/fs/autofs/waitq.c
4 *
5 * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
Ian Kent5c0a32f2006-03-27 01:14:55 -08006 * Copyright 2001-2006 Ian Kent <raven@themaw.net>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
8 * This file is part of the Linux kernel and is made available under
9 * the terms of the GNU General Public License, version 2, or at your
10 * option, any later version, incorporated herein by reference.
11 *
12 * ------------------------------------------------------------------------- */
13
14#include <linux/slab.h>
15#include <linux/time.h>
16#include <linux/signal.h>
17#include <linux/file.h>
18#include "autofs_i.h"
19
20/* We make this a static variable rather than a part of the superblock; it
21 is better if we don't reassign numbers easily even across filesystems */
22static autofs_wqt_t autofs4_next_wait_queue = 1;
23
24/* These are the signals we allow interrupting a pending mount */
25#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT))
26
27void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
28{
29 struct autofs_wait_queue *wq, *nwq;
30
Ian Kent5a11d4d2008-07-23 21:30:17 -070031 mutex_lock(&sbi->wq_mutex);
32 if (sbi->catatonic) {
33 mutex_unlock(&sbi->wq_mutex);
34 return;
35 }
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 DPRINTK("entering catatonic mode");
38
39 sbi->catatonic = 1;
40 wq = sbi->queues;
41 sbi->queues = NULL; /* Erase all wait queues */
Ian Kente77fbdd2006-03-27 01:14:49 -080042 while (wq) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 nwq = wq->next;
44 wq->status = -ENOENT; /* Magic is gone - report failure */
Tim Gardner5140a8c2013-03-01 19:46:48 +080045 kfree(wq->name.name);
46 wq->name.name = NULL;
Ian Kent296f7bf2008-07-23 21:30:21 -070047 wq->wait_ctr--;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 wake_up_interruptible(&wq->queue);
49 wq = nwq;
50 }
Ian Kentba8df432006-11-14 02:03:29 -080051 fput(sbi->pipe); /* Close the pipe */
52 sbi->pipe = NULL;
Ian Kent5a11d4d2008-07-23 21:30:17 -070053 sbi->pipefd = -1;
54 mutex_unlock(&sbi->wq_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055}
56
Al Virod668dc52012-01-10 22:35:38 -050057static int autofs4_write(struct autofs_sb_info *sbi,
58 struct file *file, const void *addr, int bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
60 unsigned long sigpipe, flags;
61 mm_segment_t fs;
62 const char *data = (const char *)addr;
63 ssize_t wr = 0;
64
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 sigpipe = sigismember(&current->pending.signal, SIGPIPE);
66
67 /* Save pointer to user space and point back to kernel space */
68 fs = get_fs();
69 set_fs(KERNEL_DS);
70
Al Virod668dc52012-01-10 22:35:38 -050071 mutex_lock(&sbi->pipe_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 while (bytes &&
73 (wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) {
74 data += wr;
75 bytes -= wr;
76 }
Ian Kent86380942012-01-13 20:41:46 +080077 mutex_unlock(&sbi->pipe_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
79 set_fs(fs);
80
81 /* Keep the currently executing process from receiving a
82 SIGPIPE unless it was already supposed to get one */
83 if (wr == -EPIPE && !sigpipe) {
84 spin_lock_irqsave(&current->sighand->siglock, flags);
85 sigdelset(&current->pending.signal, SIGPIPE);
86 recalc_sigpending();
87 spin_unlock_irqrestore(&current->sighand->siglock, flags);
88 }
89
90 return (bytes > 0);
91}
Linus Torvaldsfcbf94b2012-04-28 08:29:56 -070092
Linus Torvalds1da177e2005-04-16 15:20:36 -070093static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
94 struct autofs_wait_queue *wq,
95 int type)
96{
Ian Kente8514472007-02-20 13:58:09 -080097 union {
98 struct autofs_packet_hdr hdr;
99 union autofs_packet_union v4_pkt;
100 union autofs_v5_packet_union v5_pkt;
101 } pkt;
Ian Kente64be332008-07-23 21:30:20 -0700102 struct file *pipe = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 size_t pktsz;
104
105 DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d",
Linus Torvalds2f84dd72011-08-08 11:55:20 -0700106 (unsigned long) wq->wait_queue_token, wq->name.len, wq->name.name, type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
108 memset(&pkt,0,sizeof pkt); /* For security reasons */
109
110 pkt.hdr.proto_version = sbi->version;
111 pkt.hdr.type = type;
Al Viro87533332012-01-10 22:24:48 -0500112
Ian Kent5c0a32f2006-03-27 01:14:55 -0800113 switch (type) {
114 /* Kernel protocol v4 missing and expire packets */
115 case autofs_ptype_missing:
116 {
Ian Kente8514472007-02-20 13:58:09 -0800117 struct autofs_packet_missing *mp = &pkt.v4_pkt.missing;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119 pktsz = sizeof(*mp);
120
121 mp->wait_queue_token = wq->wait_queue_token;
Jeff Moyer70b52a02008-07-23 21:30:16 -0700122 mp->len = wq->name.len;
123 memcpy(mp->name, wq->name.name, wq->name.len);
124 mp->name[wq->name.len] = '\0';
Ian Kent5c0a32f2006-03-27 01:14:55 -0800125 break;
126 }
127 case autofs_ptype_expire_multi:
128 {
Ian Kente8514472007-02-20 13:58:09 -0800129 struct autofs_packet_expire_multi *ep = &pkt.v4_pkt.expire_multi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131 pktsz = sizeof(*ep);
132
133 ep->wait_queue_token = wq->wait_queue_token;
Jeff Moyer70b52a02008-07-23 21:30:16 -0700134 ep->len = wq->name.len;
135 memcpy(ep->name, wq->name.name, wq->name.len);
136 ep->name[wq->name.len] = '\0';
Ian Kent5c0a32f2006-03-27 01:14:55 -0800137 break;
138 }
139 /*
140 * Kernel protocol v5 packet for handling indirect and direct
141 * mount missing and expire requests
142 */
143 case autofs_ptype_missing_indirect:
144 case autofs_ptype_expire_indirect:
145 case autofs_ptype_missing_direct:
146 case autofs_ptype_expire_direct:
147 {
Ian Kente8514472007-02-20 13:58:09 -0800148 struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet;
Eric W. Biederman45634cd2012-02-07 16:18:52 -0800149 struct user_namespace *user_ns = sbi->pipe->f_cred->user_ns;
Ian Kent5c0a32f2006-03-27 01:14:55 -0800150
Linus Torvaldsfcbf94b2012-04-28 08:29:56 -0700151 pktsz = sizeof(*packet);
152
Ian Kent5c0a32f2006-03-27 01:14:55 -0800153 packet->wait_queue_token = wq->wait_queue_token;
Jeff Moyer70b52a02008-07-23 21:30:16 -0700154 packet->len = wq->name.len;
155 memcpy(packet->name, wq->name.name, wq->name.len);
156 packet->name[wq->name.len] = '\0';
Ian Kent5c0a32f2006-03-27 01:14:55 -0800157 packet->dev = wq->dev;
158 packet->ino = wq->ino;
Eric W. Biederman45634cd2012-02-07 16:18:52 -0800159 packet->uid = from_kuid_munged(user_ns, wq->uid);
160 packet->gid = from_kgid_munged(user_ns, wq->gid);
Ian Kent5c0a32f2006-03-27 01:14:55 -0800161 packet->pid = wq->pid;
162 packet->tgid = wq->tgid;
163 break;
164 }
165 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 printk("autofs4_notify_daemon: bad type %d!\n", type);
Al Viro87533332012-01-10 22:24:48 -0500167 mutex_unlock(&sbi->wq_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 return;
169 }
170
Al Virocb0942b2012-08-27 14:48:26 -0400171 pipe = get_file(sbi->pipe);
Al Viro87533332012-01-10 22:24:48 -0500172
Ian Kente64be332008-07-23 21:30:20 -0700173 mutex_unlock(&sbi->wq_mutex);
174
Al Virod668dc52012-01-10 22:35:38 -0500175 if (autofs4_write(sbi, pipe, &pkt, pktsz))
Al Viro87533332012-01-10 22:24:48 -0500176 autofs4_catatonic_mode(sbi);
177 fput(pipe);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178}
179
180static int autofs4_getpath(struct autofs_sb_info *sbi,
181 struct dentry *dentry, char **name)
182{
183 struct dentry *root = sbi->sb->s_root;
184 struct dentry *tmp;
Nick Piggin949854d2011-01-07 17:49:37 +1100185 char *buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 char *p;
Nick Piggin949854d2011-01-07 17:49:37 +1100187 int len;
188 unsigned seq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
Nick Piggin949854d2011-01-07 17:49:37 +1100190rename_retry:
191 buf = *name;
192 len = 0;
Nick Pigginb5c84bf2011-01-07 17:49:38 +1100193
Nick Piggin949854d2011-01-07 17:49:37 +1100194 seq = read_seqbegin(&rename_lock);
195 rcu_read_lock();
Ian Kente7854722011-03-25 01:51:31 +0800196 spin_lock(&sbi->fs_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
198 len += tmp->d_name.len + 1;
199
Ian Kentcab09362008-05-01 04:35:07 -0700200 if (!len || --len > NAME_MAX) {
Ian Kente7854722011-03-25 01:51:31 +0800201 spin_unlock(&sbi->fs_lock);
Nick Piggin949854d2011-01-07 17:49:37 +1100202 rcu_read_unlock();
203 if (read_seqretry(&rename_lock, seq))
204 goto rename_retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 return 0;
206 }
207
208 *(buf + len) = '\0';
209 p = buf + len - dentry->d_name.len;
210 strncpy(p, dentry->d_name.name, dentry->d_name.len);
211
212 for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) {
213 *(--p) = '/';
214 p -= tmp->d_name.len;
215 strncpy(p, tmp->d_name.name, tmp->d_name.len);
216 }
Ian Kente7854722011-03-25 01:51:31 +0800217 spin_unlock(&sbi->fs_lock);
Nick Piggin949854d2011-01-07 17:49:37 +1100218 rcu_read_unlock();
219 if (read_seqretry(&rename_lock, seq))
220 goto rename_retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222 return len;
223}
224
Ian Kenta5370552006-05-15 09:43:51 -0700225static struct autofs_wait_queue *
Jeff Moyer70b52a02008-07-23 21:30:16 -0700226autofs4_find_wait(struct autofs_sb_info *sbi, struct qstr *qstr)
Ian Kenta5370552006-05-15 09:43:51 -0700227{
228 struct autofs_wait_queue *wq;
229
230 for (wq = sbi->queues; wq; wq = wq->next) {
Jeff Moyer70b52a02008-07-23 21:30:16 -0700231 if (wq->name.hash == qstr->hash &&
232 wq->name.len == qstr->len &&
233 wq->name.name &&
234 !memcmp(wq->name.name, qstr->name, qstr->len))
Ian Kenta5370552006-05-15 09:43:51 -0700235 break;
236 }
237 return wq;
238}
239
Ian Kenta1362fe2008-07-23 21:30:19 -0700240/*
241 * Check if we have a valid request.
242 * Returns
243 * 1 if the request should continue.
244 * In this case we can return an autofs_wait_queue entry if one is
245 * found or NULL to idicate a new wait needs to be created.
246 * 0 or a negative errno if the request shouldn't continue.
247 */
248static int validate_request(struct autofs_wait_queue **wait,
249 struct autofs_sb_info *sbi,
250 struct qstr *qstr,
251 struct dentry*dentry, enum autofs_notify notify)
252{
253 struct autofs_wait_queue *wq;
254 struct autofs_info *ino;
255
Al Viro4041bcd2012-01-10 22:20:12 -0500256 if (sbi->catatonic)
257 return -ENOENT;
258
Ian Kenta1362fe2008-07-23 21:30:19 -0700259 /* Wait in progress, continue; */
260 wq = autofs4_find_wait(sbi, qstr);
261 if (wq) {
262 *wait = wq;
263 return 1;
264 }
265
266 *wait = NULL;
267
268 /* If we don't yet have any info this is a new request */
269 ino = autofs4_dentry_ino(dentry);
270 if (!ino)
271 return 1;
272
273 /*
274 * If we've been asked to wait on an existing expire (NFY_NONE)
275 * but there is no wait in the queue ...
276 */
277 if (notify == NFY_NONE) {
278 /*
279 * Either we've betean the pending expire to post it's
280 * wait or it finished while we waited on the mutex.
281 * So we need to wait till either, the wait appears
282 * or the expire finishes.
283 */
284
285 while (ino->flags & AUTOFS_INF_EXPIRING) {
286 mutex_unlock(&sbi->wq_mutex);
287 schedule_timeout_interruptible(HZ/10);
288 if (mutex_lock_interruptible(&sbi->wq_mutex))
289 return -EINTR;
290
Al Viro4041bcd2012-01-10 22:20:12 -0500291 if (sbi->catatonic)
292 return -ENOENT;
293
Ian Kenta1362fe2008-07-23 21:30:19 -0700294 wq = autofs4_find_wait(sbi, qstr);
295 if (wq) {
296 *wait = wq;
297 return 1;
298 }
299 }
300
301 /*
302 * Not ideal but the status has already gone. Of the two
303 * cases where we wait on NFY_NONE neither depend on the
304 * return status of the wait.
305 */
306 return 0;
307 }
308
309 /*
310 * If we've been asked to trigger a mount and the request
311 * completed while we waited on the mutex ...
312 */
313 if (notify == NFY_MOUNT) {
Ian Kent9e3fea12011-01-14 18:46:30 +0000314 struct dentry *new = NULL;
315 int valid = 1;
316
Ian Kenta1362fe2008-07-23 21:30:19 -0700317 /*
Ian Kent463aea12009-06-09 16:26:24 -0700318 * If the dentry was successfully mounted while we slept
319 * on the wait queue mutex we can return success. If it
320 * isn't mounted (doesn't have submounts for the case of
321 * a multi-mount with no mount at it's base) we can
322 * continue on and create a new request.
323 */
Ian Kent9e3fea12011-01-14 18:46:30 +0000324 if (!IS_ROOT(dentry)) {
325 if (dentry->d_inode && d_unhashed(dentry)) {
326 struct dentry *parent = dentry->d_parent;
327 new = d_lookup(parent, &dentry->d_name);
328 if (new)
329 dentry = new;
330 }
331 }
Ian Kent463aea12009-06-09 16:26:24 -0700332 if (have_submounts(dentry))
Ian Kent9e3fea12011-01-14 18:46:30 +0000333 valid = 0;
334
335 if (new)
336 dput(new);
337 return valid;
Ian Kenta1362fe2008-07-23 21:30:19 -0700338 }
339
340 return 1;
341}
342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
344 enum autofs_notify notify)
345{
346 struct autofs_wait_queue *wq;
Jeff Moyer70b52a02008-07-23 21:30:16 -0700347 struct qstr qstr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 char *name;
Ian Kenta1362fe2008-07-23 21:30:19 -0700349 int status, ret, type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351 /* In catatonic mode, we don't wait for nobody */
Ian Kente77fbdd2006-03-27 01:14:49 -0800352 if (sbi->catatonic)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 return -ENOENT;
Ian Kenta1362fe2008-07-23 21:30:19 -0700354
Ian Kentc72305b2008-07-23 21:30:23 -0700355 if (!dentry->d_inode) {
356 /*
357 * A wait for a negative dentry is invalid for certain
358 * cases. A direct or offset mount "always" has its mount
359 * point directory created and so the request dentry must
360 * be positive or the map key doesn't exist. The situation
361 * is very similar for indirect mounts except only dentrys
362 * in the root of the autofs file system may be negative.
363 */
Ian Kenta92daf62009-01-06 14:42:08 -0800364 if (autofs_type_trigger(sbi->type))
Ian Kentc72305b2008-07-23 21:30:23 -0700365 return -ENOENT;
366 else if (!IS_ROOT(dentry->d_parent))
367 return -ENOENT;
368 }
Ian Kenteb3b1762008-07-23 21:30:22 -0700369
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
371 if (!name)
372 return -ENOMEM;
373
Ian Kent5c0a32f2006-03-27 01:14:55 -0800374 /* If this is a direct mount request create a dummy name */
Ian Kenta92daf62009-01-06 14:42:08 -0800375 if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type))
Jeff Moyer70b52a02008-07-23 21:30:16 -0700376 qstr.len = sprintf(name, "%p", dentry);
Ian Kent5c0a32f2006-03-27 01:14:55 -0800377 else {
Jeff Moyer70b52a02008-07-23 21:30:16 -0700378 qstr.len = autofs4_getpath(sbi, dentry, &name);
379 if (!qstr.len) {
Ian Kent5c0a32f2006-03-27 01:14:55 -0800380 kfree(name);
381 return -ENOENT;
382 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 }
Jeff Moyer70b52a02008-07-23 21:30:16 -0700384 qstr.name = name;
385 qstr.hash = full_name_hash(name, qstr.len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
Ian Kentf4c7da02008-07-23 21:30:19 -0700387 if (mutex_lock_interruptible(&sbi->wq_mutex)) {
388 kfree(qstr.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 return -EINTR;
Ian Kentf4c7da02008-07-23 21:30:19 -0700390 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
Ian Kenta1362fe2008-07-23 21:30:19 -0700392 ret = validate_request(&wq, sbi, &qstr, dentry, notify);
393 if (ret <= 0) {
Al Viro4041bcd2012-01-10 22:20:12 -0500394 if (ret != -EINTR)
Ian Kenta5370552006-05-15 09:43:51 -0700395 mutex_unlock(&sbi->wq_mutex);
Ian Kenta1362fe2008-07-23 21:30:19 -0700396 kfree(qstr.name);
397 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 }
399
Ian Kente77fbdd2006-03-27 01:14:49 -0800400 if (!wq) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 /* Create a new wait queue */
402 wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
Ian Kente77fbdd2006-03-27 01:14:49 -0800403 if (!wq) {
Jeff Moyer70b52a02008-07-23 21:30:16 -0700404 kfree(qstr.name);
Ingo Molnar1d5599e2006-03-23 03:00:41 -0800405 mutex_unlock(&sbi->wq_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 return -ENOMEM;
407 }
408
409 wq->wait_queue_token = autofs4_next_wait_queue;
410 if (++autofs4_next_wait_queue == 0)
411 autofs4_next_wait_queue = 1;
412 wq->next = sbi->queues;
413 sbi->queues = wq;
414 init_waitqueue_head(&wq->queue);
Jeff Moyer70b52a02008-07-23 21:30:16 -0700415 memcpy(&wq->name, &qstr, sizeof(struct qstr));
Ian Kent5c0a32f2006-03-27 01:14:55 -0800416 wq->dev = autofs4_get_dev(sbi);
417 wq->ino = autofs4_get_ino(sbi);
David Howells0eb790e2008-11-14 10:38:46 +1100418 wq->uid = current_uid();
419 wq->gid = current_gid();
Ian Kent5c0a32f2006-03-27 01:14:55 -0800420 wq->pid = current->pid;
421 wq->tgid = current->tgid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 wq->status = -EINTR; /* Status return if interrupted */
Ian Kent296f7bf2008-07-23 21:30:21 -0700423 wq->wait_ctr = 2;
Ian Kent3e7b1912006-03-27 01:14:59 -0800424
Ian Kent5c0a32f2006-03-27 01:14:55 -0800425 if (sbi->version < 5) {
426 if (notify == NFY_MOUNT)
427 type = autofs_ptype_missing;
428 else
429 type = autofs_ptype_expire_multi;
430 } else {
431 if (notify == NFY_MOUNT)
Ian Kenta92daf62009-01-06 14:42:08 -0800432 type = autofs_type_trigger(sbi->type) ?
Ian Kent5c0a32f2006-03-27 01:14:55 -0800433 autofs_ptype_missing_direct :
434 autofs_ptype_missing_indirect;
435 else
Ian Kenta92daf62009-01-06 14:42:08 -0800436 type = autofs_type_trigger(sbi->type) ?
Ian Kent5c0a32f2006-03-27 01:14:55 -0800437 autofs_ptype_expire_direct :
438 autofs_ptype_expire_indirect;
439 }
Ian Kent4dcd00b2005-05-01 08:59:16 -0700440
Ian Kent682d4fc2005-07-07 17:57:02 -0700441 DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
Jeff Moyer70b52a02008-07-23 21:30:16 -0700442 (unsigned long) wq->wait_queue_token, wq->name.len,
443 wq->name.name, notify);
Ian Kent4dcd00b2005-05-01 08:59:16 -0700444
Al Viro606035e2013-09-14 17:32:12 -0400445 /* autofs4_notify_daemon() may block; it will unlock ->wq_mutex */
Ian Kent4dcd00b2005-05-01 08:59:16 -0700446 autofs4_notify_daemon(sbi, wq, type);
Ian Kenta5370552006-05-15 09:43:51 -0700447 } else {
Ian Kent296f7bf2008-07-23 21:30:21 -0700448 wq->wait_ctr++;
Ian Kenta5370552006-05-15 09:43:51 -0700449 DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
Jeff Moyer70b52a02008-07-23 21:30:16 -0700450 (unsigned long) wq->wait_queue_token, wq->name.len,
451 wq->name.name, notify);
Al Viro606035e2013-09-14 17:32:12 -0400452 mutex_unlock(&sbi->wq_mutex);
453 kfree(qstr.name);
Ian Kent4dcd00b2005-05-01 08:59:16 -0700454 }
455
Ian Kent5a11d4d2008-07-23 21:30:17 -0700456 /*
457 * wq->name.name is NULL iff the lock is already released
458 * or the mount has been made catatonic.
459 */
Jeff Moyer70b52a02008-07-23 21:30:16 -0700460 if (wq->name.name) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 /* Block all but "shutdown" signals while waiting */
462 sigset_t oldset;
463 unsigned long irqflags;
464
465 spin_lock_irqsave(&current->sighand->siglock, irqflags);
466 oldset = current->blocked;
467 siginitsetinv(&current->blocked, SHUTDOWN_SIGS & ~oldset.sig[0]);
468 recalc_sigpending();
469 spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
470
Jeff Moyer70b52a02008-07-23 21:30:16 -0700471 wait_event_interruptible(wq->queue, wq->name.name == NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
473 spin_lock_irqsave(&current->sighand->siglock, irqflags);
474 current->blocked = oldset;
475 recalc_sigpending();
476 spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
477 } else {
478 DPRINTK("skipped sleeping");
479 }
480
481 status = wq->status;
482
Ian Kentc0f54d32008-10-15 22:02:52 -0700483 /*
484 * For direct and offset mounts we need to track the requester's
485 * uid and gid in the dentry info struct. This is so it can be
486 * supplied, on request, by the misc device ioctl interface.
487 * This is needed during daemon resatart when reconnecting
488 * to existing, active, autofs mounts. The uid and gid (and
489 * related string values) may be used for macro substitution
490 * in autofs mount maps.
491 */
492 if (!status) {
493 struct autofs_info *ino;
494 struct dentry *de = NULL;
495
496 /* direct mount or browsable map */
497 ino = autofs4_dentry_ino(dentry);
498 if (!ino) {
499 /* If not lookup actual dentry used */
500 de = d_lookup(dentry->d_parent, &dentry->d_name);
501 if (de)
502 ino = autofs4_dentry_ino(de);
503 }
504
505 /* Set mount requester */
506 if (ino) {
507 spin_lock(&sbi->fs_lock);
508 ino->uid = wq->uid;
509 ino->gid = wq->gid;
510 spin_unlock(&sbi->fs_lock);
511 }
512
513 if (de)
514 dput(de);
515 }
516
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 /* Are we the last process to need status? */
Ian Kent296f7bf2008-07-23 21:30:21 -0700518 mutex_lock(&sbi->wq_mutex);
519 if (!--wq->wait_ctr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 kfree(wq);
Ian Kent296f7bf2008-07-23 21:30:21 -0700521 mutex_unlock(&sbi->wq_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
523 return status;
524}
525
526
527int autofs4_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_token, int status)
528{
529 struct autofs_wait_queue *wq, **wql;
530
Ingo Molnar1d5599e2006-03-23 03:00:41 -0800531 mutex_lock(&sbi->wq_mutex);
Stephen Hemmingerc80544d2007-10-18 03:07:05 -0700532 for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) {
Ian Kente77fbdd2006-03-27 01:14:49 -0800533 if (wq->wait_queue_token == wait_queue_token)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534 break;
535 }
536
Ian Kente77fbdd2006-03-27 01:14:49 -0800537 if (!wq) {
Ingo Molnar1d5599e2006-03-23 03:00:41 -0800538 mutex_unlock(&sbi->wq_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 return -EINVAL;
540 }
541
542 *wql = wq->next; /* Unlink from chain */
Jeff Moyer70b52a02008-07-23 21:30:16 -0700543 kfree(wq->name.name);
544 wq->name.name = NULL; /* Do not wait on this queue */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 wq->status = status;
Ian Kent296f7bf2008-07-23 21:30:21 -0700546 wake_up_interruptible(&wq->queue);
547 if (!--wq->wait_ctr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 kfree(wq);
Ian Kent296f7bf2008-07-23 21:30:21 -0700549 mutex_unlock(&sbi->wq_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
551 return 0;
552}
553